Air-compressor



2 Sheets-Sheet 1.

(No Model.)

T. H. ROBERTS.

. AIR COMPRESSOR.

No. 597,223. Patented Jan. 11,1898.

f wn/m.- Wdzes homers/i Floerfs,

UNITED STATES PATENT @rricn.

THOMAS HERBERT ROBERTS, OF DETROIT, MICHIGAN.

AIR-COMPRESSOR.

SPECIFICATION forming part of Letters Patent No. 597,223, dated January 11, 1898.

Application filed December 14, 1896. Serial No. 615,686. (No model.)

To all 1072,0727, it may concern:

Be it known that I, THOMAS HERBERT Ros- ERTS, a citizen of the United States, residing at Detroit, in the county of \Vayne and State of Michigan, have invented certain new and useful Improvements in Air-Compressors, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to a new construction of air-compressor especially adapted for the equipment of electric cars with air-brakes; and to this end the invention consists in the novel construction, arrangement, and combi nation of parts whereby extreme simplicity and compactness are obtained, all as more fully hereinafter described, and shown in the drawings, in which- Figure 1 is a side elevation, partly in vertical central section, of my improved air-compressor. Fig. 2 is a horizontal section thereof on line so a A is the compressed-air tank, provided with lateral flanges B for supporting it in upright position upon suitable supports, such as the floor-timbers (J of a car.

D is the cylinder of the air-pump; E, the piston; F, the piston-rod, and G and H are valves seated, respectively, on the upper and lower end of the pump-cylinder. The valve G is seated by gravity and has a stuffing-box I for the pump-piston to pass through, and the valve H is upheld by a spring J, supported by a skeleton cap K, which is screwed on the pump-cylinder.

The pump-cylinder is provided midway of its length with a head L, in which are formed a series of radial air-passages M, which communicate at their inner ends through the annular series of ports N into the air-cylinder, while the outer ends open into the atmosphere. This head is secured within the airtank, which to this end is formed of an upper and lower section, each provided with annular flanges a, between which the head is bolted in, the flanges being preferably formed with' annular lips Z), adapted to engage with corresponding grooves in the head, all so arranged as to form an air-tight jointbetween the parts.

The head L supports the air-pump within the air-tank in the axial line thereof, and it is provided with suitable openings 0, through which the compartments above and below "the head communicate.

On top of the tank is secured a gallowsframe 0, the sides of which form vertical guide-bearings for the slotted head P, carried by the piston-rod, which latter extends,

impart a suitable reciprocating motion to the pump-piston.

The drive-shaft Q extends on one side of the frame 0 and carries the armature of a revolving electric motor S of any suitable description, the free end of the shaft being supported in a bracket T, which also supports the stationary parts of the motor, all so arranged as to utilize the power of an electric current applied to the motor for operating the air-pump.

It will be seen that the piston of the airpump alternately compresses the air in the opposite ends of the cylinder, and by the operation of the valves G and H it is stored in the tank, while fresh air is constantly admitted through the ports N from the atmosphere. It will be seen that this air-compressor is of an upright type which requires but very little floor space, practically only what is required for the base of the air-tank to rest on, and by placing the lateral supporting-flanges 13 above the base the available space between the floorjoist is utilized to drop the tank partly below the floor. Further1nore,the drive mechanism is such that the pump works without jar or noise, and the pump, being entirely iuclosed within the tank, muffles the noise incidental to the working of air-pumps in such a manner that it does away entirely with the objections with, and the necessity of keeping the parts Well oiled does not create any nuisance. To gain ready access to the pump,a suitable handhole is placed in the tank.

For the reasons above given my air-pump is especially available for use on electric cars, dwelling-houses, offices, &c., Where the demand for such a compressor is constantly in creasing.

What I claim as my invention is- 1. In an air-compressor, the combination of an air-tank formed of two sections, and an airpump secured in between the sections, said pump having its pump-cylinder formed with a supporting means fitted in and secured between the sections and provided With a series of air-inlet passages extending through said supporting means into the pump-cylinder.

2. In an air-compressor, the combination of an air-tank formed of a section, having supporting-flanges, and a second section, an airpump having its cylinder provided with an aperturedweb bolted in between the said sections of the tank, radial air-passages extending through the Web into the pump-cylinder and forming an annular series of inlet-ports centrally of the pump, valves seated on the ends of the pump-cylinder and a reciprocating piston having a piston-rod extending through a stufiing-box in the tank and operated by drive mechanism supported on the tank.

3. In an air-compressor, the combination of the airtank forming a supporting-base, a

pump having its cylinder provided with a Web bolted in between two sections of the tank and provided with radialair-passages from the outside into the pump-cylinder, a reciprocating piston having a piston rod extending through a stuffing-box in the tank and drive mechanism supported on the tank.

4. In an air-compressor, the combination of a tank or reservoir for compressed air, a pumpcylinder inclosed within said reservoir intermediate its ends and provided with air-inlet conduits communicating with the external air, movable caps for said pump-cylinder constitut-in g the exhaust-valves thereof, a piston in said cylinder, and means for operating the piston from without the reservoir or tank, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

THOMAS HERBERT ROBERTS.

\Vitnessesz' O'rro FIBARTHEL, A. L. HABBY. 

